The rapid development of smaller, lighter, and higher performance electronic and communication equipment has required the development of high performance and large capacity batteries to power such equipment. Lithium-sulfur batteries are of interest because they have the highest theoretical energy density, 2800 Wh/kg (1675 mAh/g), as compared to other batteries. In addition, sulfur is an abundant and inexpensive material, and is also environmentally friendly.
The choice of a binder is critical for determining battery performance. A binder is typically used to adhere positive active materials of the battery to each other and for subsequent adherence on a current collector or electrode. The requirements for the binder typically include chemical resistance to polysulfides; an ability to enhance the mechanical integrity of the positive electrode; stability at battery working temperatures; solubility in organic solvents used in slurry; insolubility in electrolytes; and high adherence properties to sulfur containing positive active materials of the battery.
Except for the high adherence, these physical properties have a significant effect on battery performance. Some materials satisfy such physical properties except for having high adherence, so a binder using these materials will have relatively low adherence.